SqlBulkCopy - Execution Timeout Expired. The timeout period elapsed prior to completion of the operation or the server is not responding.

Problem

You execute the method WriteToServer, and the following error is thrown:

Execution Timeout Expired. The timeout period elapsed prior to completion of the operation or the server is not responding.

// Oops! The specified bulkCopyTimeout value is to low!
bulkCopyTimeout = 1;

using (var connection = new SqlConnection(My.Config.ConnectionStrings.BulkOperations))
{
    connection.Open();

    using (var bulkCopy = new SqlBulkCopy(connection))
    {
        // SET BulkCopyTimeout value.
        bulkCopy.BulkCopyTimeout = bulkCopyTimeout;
        
        bulkCopy.DestinationTableName = destinationName;
        bulkCopy.WriteToServer(dt);
    }
}

Solution

Cause

• The bulk copy take more time to execute than the BulkCopyTimeout specified.

Fix

• INCREASE the BulkCopyTimeout value (default = 30s).
• DECREASE the BatchSize value (default = unlimited).

The bulkCopyTimeout is by batch, not for the whole bulk operation.